1. Field of the Invention
The invention relates to generating navigation routes using user-supplied trail data, and more particularly, to generating a suggested navigation route using a combination of roads belonging to a road network and off-road trail data provided by a user.
2. Description of the Prior Art
Global Positioning System (GPS) based navigation devices are well known and are widely employed as in-car navigation devices. Common functions of a navigation device include providing a map database for generating navigation instructions that are then shown on a display of the navigation device. These navigation devices are often mounted on or in the dashboard of a vehicle using a suction mount or other mounting means.
The term “navigation device” refers to a device that enables a user to navigate to a pre-defined destination. The device may have an internal system for receiving location data, such as a GPS receiver, or may merely be connectable to a receiver that can receive location data. The device may compute a route itself, or communicate with a remote server that computes the route and provides navigation information to the device, or a hybrid device in which the device itself and a remote server both play a role in the route computation process. Portable GPS navigation devices are not permanently integrated into a vehicle but instead are devices that can readily be mounted in or otherwise used inside a vehicle. Generally (but not necessarily), they are fully self-contained—i.e. include an internal GPS antenna, navigation software and maps and can hence plot and display a route to be taken.
Personal navigation devices are becoming more popular, and many variations of personal navigation devices and navigation applications have been developed. In each variant, geographical coordinates are received, and then the user's position on a map can be shown as well as where the user has traveled and where the user is heading.
For consumer products, there are three popular kinds of applications using navigation devices. First, vehicle navigation applications are widely used for offering navigation guidance to a user driving a vehicle. Second, outdoor applications allow users to store their locations as waypoints and remember history of movements as multi-segment “bread-crumb” tracks. Third, fitness applications, such as those used by runners and bicyclists, can record tracks, calculate distances traveled, speeds, and calories burned, and can also offer some navigation assistance.
Despite the wide variety of applications using navigation devices, not every user may find an application which satisfies the user's requirements during a particular activity. For instance, the user may use a vehicle navigation application to guide the user to a trail head of a hiking trail. The user may then use an outdoor application to record the user's hiking activity. The user might also want to load the hiking activity data into a fitness application in order to determine how many calories the user has burned.
Unfortunately, it is very inconvenient to need to switch between different applications in order to perform different tasks. Thus, there is a growing need to combining different features together into more complete applications.